Archive for September 22nd, 2009

Reader Mike had sent along this great post from a California math teacher who analyzed supermarket checkout times (data, as pictured above, was provided by the supermarket manager). I’m slow to post this and it has now been around a lot, but this was catnip to me as I love these sort of operational/logistical/queue problems (and this relates a bit to the airport walkway problem), particularly when they seem to exhibit that classic “slower is faster/faster is slower” effect. Not to mention that “other lane is always moving faster” problem that plagues us in traffic is a very real issue in queuing as well (and is partially why some outfits use single lines).

Among the many interesting findings:

The express lane isn’t faster. The manager backed me up on this one. You attract more people holding fewer total items, but as the data shows above, when you add one person to the line, you’re adding 48 extra seconds to the line length (that’s “tender time” added to “other time”) without even considering the items in her cart. Meanwhile, an extra item only costs you an extra 2.8 seconds. Therefore, you’d rather add 17 more items to the line than one extra person! I can’t believe I’m dropping exclamation points in an essay on grocery shopping but that’s how this stuff makes me feel.

There’s ways this can be applied to traffic, but reader Mike was wondering about those express/local lanes on highways. I only know anecdotal stuff here, like stories of engineers changing the estimated times on both segments when they really want people to use one or the other. But this is a bit of a guessing game every time I approach the George Washington Bridge on I-80. I’ve been burned many times by the express lane — is it the very wording, which fools me into thinking it’s a better way to go than that inevitably cluttered and slower “local” lane? It of course depends on many variables, like the intended destination of traffic, etc.

Maybe there’s some geeky studies somewhere of tolling as well; exact change lanes versus others, etc.; though those are likely to be outmoded with EZ-Pass etc.

BATON ROUGE, LA (WAFB) – A man was booked into the East Baton Rouge Parish Prison on a DWI charge and numerous traffic violations after he slammed into a Baton Rouge police car early Friday morning.

Baton Rouge police arrested Leper Lewis, 49, of Baton Rouge in the crash. It happened around 1:30 a.m. on Evangeline Street near I-110.

Lewis was charged with second offense DWI, reckless operation, failure to maintain control, driving on the wrong side of the road, expired driver’s license and no insurance.

According to police, he hit the police car after coming around a curve in the wrong lane on Evangeline. The collision was almost head-on and the impact spun the police unit around and off the road.

The 31-year-old corporal suffered only minor injuries and was okay. His police dog was also fine. However, the corporal’s police-issued 2008 Dodge Charger was heavily damaged and had to be towed from the scene.

It received some damage to the front of it and along the side. The entire length of the passenger side of the police car was damaged.

The other vehicle was damaged to the point where it had to be towed as well. Its damage was primarily to the front of the car.

The officer was patrolling in the 2500 block of Evangeline when the crash occurred. The street was temporarily closed to traffic while police investigated the accident.

Posted on Tuesday, September 22nd, 2009 at 8:43 am by: Tom VanderbiltComments Off on The Accidental Journalist (an occasional series chronicling how predictable, preventable crashes are turned into accidents). Click here to leave a comment.

How We Drive is the companion blog to Tom Vanderbilt’s New York Times bestselling book, Traffic: Why We Drive the Way We Do (and What It Says About Us), published by Alfred A. Knopf in the U.S. and Canada, Penguin in the U.K, and in languages other than English by a number of other fine publishers worldwide.